Average Surface Roughness Research Articles

A two-step hydrothermal method for micro/nanotextured titanium implants and their integration outcomes in goat mandible.

A crucial aspect of contemporary dental implant research is modifying implant microdesign to achieve early and robust osseointegration. This study describes a new facile subtraction approach for microdesign modification of titanium implants using akali-hydrothermal followed by ion-exchange reaction (AHIE) in a salt solution, and compares osseointegration performance to machined titanium alloy (negative control) implants. The morphology, wettability, and roughness of the implant surfaces were evaluated. Twenty-four cylinders (two types/side) were inserted into the right and left mandibles of six Bengal goats in opposite order. The implant-bone interface was examined at 8 and 16 weeks following implantation using radiography, micro-computed tomography, histology, and scanning electron microscopy. After AHIE treatment, average surface roughness increased marginally (p > 0.05) due to predominantly micron-scale with random nano-scale alterations, whereas wettability improved substantially (p < 0.05). In addition to micro/nano-scale defects, the AHIE treatment produced few honeycomb-like surface patterns. The AHIE implants demonstrated early and direct bone to implant body contact, and achieved stronger bone fixation in vivo than machined implants. Based on laboratory and in vivo data, we conclude that AHIE processing of titanium implants may be a promising technique for improving surface quality while assuring secure and effective osseointegration for dental implant.

Effect of burnishing strategies on surface integrity, microstructure and corrosion performance of wire arc additively manufactured AZ31 Mg alloy

AZ31 Mg alloy is an emerging material that has received considerable attention in aerospace, automotive, and temporary biodegradable implant applications owing to its attractive properties, such as low density, high specific strength, and biodegradability. Nevertheless, some shortcomings in Mg alloys are their low ductility, which is associated with challenging its manufacturing, and poor corrosion resistance associated with unreliable components. Therefore, a cold metal transfer wire arc additive manufacturing (CMT-WAAM) process is used to manufacture AZ31 Mg alloy and achieved 29.4 % ductility by controlling the gas porosity, keyhole porosity, and internal cracks. Further, severe plastic deformation is induced on the surface of deposited parts by low plasticity burnishing (LPB) with parallel and cross-pattern burnishing to modulate their surface to slow down the kinetics of the corrosion damage. The average surface roughness (Sa) of the cross-burnishing pattern is 0.235 μm, which is 123.6 % lower than the parallel burnished and 261.7 % lower than the milled specimens. The residual stress (RS) of WAAM is 40 MPa with a tensile nature; however, it is drastically reduced and develops compressive RS of 45 MPa under a parallel burnishing pattern and 62 MPa under a cross-burnishing pattern. Moreover, LPB with cross pattern deformed ∼395 μm depth of WAAMed AZ31 workpiece, which is ∼ 45 % higher than deformed depth (∼272 μm) by parallel pattern burnishing. The electrochemical corrosion rate of the WAAM specimen is 9.71 mm/year, and it is reduced to 1.82 mm/year under LPB caused by compressive residual stress and grain refinement.

Effects of Beads and Shot Peening Intensity on the Surface Integrity and Fatigue Performance of a Stainless Gear Steel

Shot peening was performed on stainless gear steel using multiple kinds of beads at multiple intensities. The effects of shot peening on surface integrity and the rotational bending fatigue performance were tested with the crack origin location observed. The results showed that the average surface roughness increases from Sa0.408 μm to Sa1.165 μm as the shot peening intensity increases, which does not necessarily lead to an increase in surface stress concentration coefficient. The compressive residual stress profile and the depth of the hardened layer increase with the increase of shot peening intensity. During ceramic bead peening, the fatigue improvement, with a maximum of 25 times, increases with the raise of intensity (0.06–0.20 mmA), while the fatigue improvement decreases when intensity (0.2–0.30 mmA) increases using cast steel shot. Based on ceramic shot peening, a method was proposed to predict the origin location of rotational bending fatigue cracks of gear stainless steel, in which the effects of surface stress concentration, compressive residual stress, and external load introduced were all considered. By using the superposition method of external load and residual stress, the maximum actual stress corresponding depth is obtained, which is the origin position of the rotational bending fatigue crack.

Tool Wear Monitoring in Hard Turning Using Sensor Fusion: An analytical approach

At present, the life expectancy of tool has become a vital aspect in the manufacturing industries, especially where materials with high hardness have more importance. Nowadays hard steel has been widely used for manufacturing of commercial parts in military aircrafts, car systems and hydraulic tools, etc. Manufacturing industries, mainly concentrates on mass production of the products with precision and accuracy. In such cases the continuous machining may weaken the tool causing tool wear which ultimately affects the quality with production rate. To avoid such an unwanted scenario, different tool wear prediction techniques have been introduced which uses cutting force signals or average chip-tool interface temperature or surface roughness signals, etc. According to the literature, different techniques are available for the pre-judgment of the tool wear that shows variation in the accuracy of prediction. Sensor fusion technique can be employed to overcome this problem by combining data from different sensors intelligently to improve the process. Sensor fusion uses this combined data to correct deficiencies of individual sensors and predict the tool wear accurately which compensate for the sudden breakage of the tool in real life applications. In this paper, a new approach of tool wear prediction has been introduced to correlate different available sensor by using sensor fusion technique. Also, a mathematical approach has been derived for the sensor fusion purpose. The experimentation has been carried out using coated carbide inserts on 55 HRC hardened steel.

Machining Eco-Friendly Jute Fiber-Reinforced Epoxy Composites Using Specially Produced Cryo-Treated and Untreated Cutting Tools

In recent years, consumers have become increasingly interested in natural, biodegradable and eco-friendly composites. Eco-friendly composites manufactured using natural reinforcing filling materials stand out with properties such as cost effectiveness and easy accessibility. For these reasons, in this research, a composite workpiece was specially manufactured using eco-friendly jute fibers. Two cost-effective cutting tools were specially produced to ensure high-quality machining of this composite workpiece. One of these specially manufactured cutting tools was subjected to DC&amp;T (deep cryogenic treatment and tempering) processes to improve its performance. At the end of the research, when the lowest and highest Fd (delamination factor) values obtained with DC&amp;T-T1 and T1 cutting tools were compared, it was observed that 5.49% and 6.23% better results were obtained with the DC&amp;T-T1 cutting tool, respectively. From the analysis of the S/N (signal-to-noise) ratios obtained using Fd values, it was found that the most appropriate machining parameters for the composite workpiece used in this investigation were the DC&amp;T-T1 cutting tool, a 2000 rev/min spindle speed and a 100 mm/min feed rate. Through ANOVAs (analyses of variance), it was discovered that the most significant parameter having an impact on the Fd values was the spindle speed, with a rate of 53.01%. Considering the lowest and highest Ra (average surface roughness) values obtained using DC&amp;T-T1 and T1 cutting tools, it was seen that 19.42% and 16.91% better results were obtained using the DC&amp;T-T1 cutting tool, respectively. In the S/N ratio analysis results obtained using Ra values, it was revealed that the most appropriate machining parameters for the composite workpiece used in this investigation were the DC&amp;T-T1 cutting tool, a 2000 rev/min spindle speed and a 100 mm/min feed rate. In the ANOVAs, it was revealed that the most significant parameter having an effect on the Ra values was the feed rate at 37.86%.

Control of surface edge roughness for an aluminum alloy mirror based on sub-aperture polishing

With current polishing methods, it is hard to guarantee roughness uniformity between the edge and inner regions of the surface. Hence, this paper develops a sub-aperture polishing method based on chemical mechanical action to remove turning periodic marks and improve surface roughness uniformity. A compliant polishing pad with a rigid tool holder is proposed to ensure that the pressure in the contact area remains constant when the polishing tool moves out the edge of the workpiece. The optimal process parameters were investigated in the full aperture polishing experiment. Numerical simulation was implemented to analyze the relationship between the overhang ratio and removal uniformity and optimize the polishing trajectory parameters. The polishing experiments with aluminum alloy mirrors reveal that the impurities inside the aluminum alloy restrict the further improvement of surface roughness. The average surface roughness is improved from 8.82 nm to 1.71 nm, and the peak and valley roughness value is reduced from 2.51 nm to 0.71 nm, which indicates the proposed sub-aperture polishing method can improve the surface roughness uniformity.

The Effect of Assist Gas Type on Nitinol Microsecond Laser Cut Edges: A Study on the Use of Oxygen, Argon, Nitrogen, Helium, and Compressed Air

Abstract Historically, the published literature for laser cutting atomically balanced nickel-titanium alloy (Nitinol) tubular devices assumes slow cut rates with an inert argon assist gas. Herein, a novel application of an exothermic reactive oxygen assist gas was employed during Nitinol laser micromachining, which enabled a 38.1 mm/s cut rate, a 4.5-times improvement from traditional argon cutting. Furthermore, this led to the realization of improved cut quality: 2-times less dross, a 2-times lower surface roughness, and a minimal heat-affected zone. Of the tested assist gases (oxygen, argon, nitrogen, helium, and compressed air), oxygen was found to provide the best cut quality, achieving dross-free cuts. Additionally, oxygen was shown to produce a relatively low arithmetic mean average surface roughness of 0.48 μm, when compared to argon at 0.85 μm. A decrease in surface roughness was found to be associated with an increase in cut rate. These findings suggest that assist gas melt flow dynamics has a higher contributing factor than laser pulse energy parameters. In-situ thermographic monitoring of the melt flow during processing demonstrated a clear difference in the melt flow pattern between a reactive oxygen assist gas and inert argon assist gas. Furthermore, with the culmination of nanoindentation analysis and microstructural characterization, it was concluded that long-pulse laser micromachining can produce cuts with negligible microstructural alterations to the bulk material. This study quantitatively demonstrates the benefits observed during laser cutting Nitinol with a reactive oxygen assist gas when compared to previous studies that employ an inert argon assist gas.

The impact of additives and dope composition on hollow fiber ultrafiltration membrane for pure water permeability

Abstract In the current work, a dry-jet wet spinning process was used for preparing the polysulfone (PS) polymer hollow fiber ultrafiltration membrane. The polysulfone (PS) polymer was prepared by phase inversion technique with two distinct additives: glycerol and polyethylene glycol (PEG). The HF membranes were characterized and their performance was compared for pure water permeability (PWP). While characterizing, scanning electron microscopy (SEM) analysis on the internal section and cross-sectional area of membranes exhibited thin finger-like structures and thick sponge-like structures, respectively. With aid of an atomic force microscopic (AFM), the average surface roughness (Ra) of extruded HF membranes was found to be 61.253 nm and 81.086 nm, respectively for the membranes prepared using glycerol and PEG as additives Wettability studies revealed that the both membranes were hydrophilic. Further, they subjected to ascertained for the average pore size, surface porosity, stretch length, and breakage load. In addition, an investigation through X-ray diffraction (XRD) analysis exhibited that the acquired fibers were amorphous. The results of these findings showed that an increase in pressure caused a rise in water flow. Though PEG-supported HF membrane was an additive that has been shown to provide a greater water flux than glycerol additive HF, its structural stability suggests that it might be employed for higher pressure applications to satisfy the necessary demand for water processing.

An Investigation on the Performance of the Ultrasonic Atomization-Based Cutting Fluid (uACF) Spray System

Nowadays, due to limited resources and manufacturers desire to keep manufacturing costs at the lowest level, minimum quantity lubrication systems stand out. Ultrasonic atomization-based cutting fluid (uACF) spray system, which is one of the minimum quantity lubrication methods, attracts attention with its low production cost and much lower cutting fluid consumption compared to conventional cooling systems. A limited number of studies have been carried out to demonstrate the performance of this innovative, compact and environmentally friendly system under real cutting conditions. uACF system was compared with spray cooling (SPR), compressed air cooling (AIR) and dry machining (DRY) conditions using similar machining parameters. Cutting speed and feed rate were selected as machining parameters. The effect of the machining parameters on the cutting force (Fc), cutting temperature (Tc), average surface roughness (Ra) and chip shrinkage coefficient (ξ) were compared with other systems. The study concluded that the uACF system can outperform or compete with different cooling methods in all performance outputs with the right choice of cutting parameter combination. In addition, the study also revealed the effects of cutting speed and feed rate levels on performance outputs under different cooling conditions. In the light of the data obtained from the study, it is concluded that the uACF system provides a good performance under real cutting conditions with a low amount of cutting fluid consumption (0.5 ml/min) with low operating cost and has a high utilisation potential.

Evaluation of Ni-Co/TiO2-CeO2 nanocomposite coatings fabricated by electro-co-deposition

Multiarticulate metal matrix composites have recently attracted the attention of many researchers. In this study, the efficacy of two reinforcement particles, TiO2 and CeO2, on the Ni-Co alloy coating was investigated. This coating is formed via the electro-co-deposition method on the copper substrate. The coated copper was examined and identified using field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) system, an electrochemical workstation, surface roughness measuring instruments, and a microhardness machine. Findings showed that adding TiO2 and CeO2 nanoparticles into Ni-Co makes better the morphology of the surface, decreases the crystalline size, and improves the corrosion resistance, wear resistance and microhardness of the Ni-Co alloy coating. For Ni-Co /TiO2-CeO2 coating, the average surface roughness value was estimated at 85 nm, which is almost twice the roughness of Ni-Co alloy coating.

Adsorption of VOC vapors on ZnPc: sensing and kinetic studies.

Thin film of sensing unit, 2,3,9,10,16,17-hexakis(3-dietylaminophenoxy)-23-etynylphenyl-(2-ferrocenyl-o-carborane)phthalocyaninato zinc(II) (ZnPc), have been deposited by spray pyrolysis technique on the quartz crystal surface with a fundamental resonance frequency of 10MHz. The surfacemorphology of the film has been studied using the contact mode atomic force microscope (AFM) technique and the average surface roughness was determined to be 36.4nm. Then, this film was exposed to the vapors of methanol, ethanol, 2-propanol, and 1-butanol with various concentrations varying between 50 and 400ppm. In addition, studies on response time and repeatability of the sensors have also been carried out. Films exhibit maximum sensing response to methanol vapor while the lowest sensitivity of the film towards 1-butanol has been observed. After an exposure time of 10min, the frequency shift of 415Hz was recorded for 400ppm methanol vapor concentration, while a frequency shift of 215Hz was observed for the same concentration of 1-butanol. The sensor was 1.30 times more sensitive to methanol vapor than ethanol and 2.00 times more sensitive to methanol than to 1-butanol. Variations in the sensitivity of the sensor have been correlated with the number of carbon groups in analyte vapors. The effect of the number of carbon groups in analyte molecule on adsorption kinetics of the film has also been investigated and compared. Adsorption isotherms of four volatile organic compounds on ZnPc were investigated at room temperature and the experimental data obtained were correlated with different existing adsorption isotherm models such as the Langmuir, the Freundlich, and Temkin model. An overall evaluation of the obtained results showed that the sensing performance, adsorption kinetic, and adsorption isotherms are dependent on the molecular size of the analyte molecules.

Ultrasonic shot peening (USSP) post-treatment of Ni laser cladding on mild steel

The ultrasonic shot peening (USSP) technique serves as a reliable post-treatment method for various industrial components to prevent functional failures. This study aims to develop hybrid Ni claddings approximately 300 µm thick on mild steel using laser cladding (LC) and USSP techniques. Morphological studies reveal that the claddings exhibit enhanced closure of cracks, increased hardness, and improved scratch resistance after peening. XRD analysis confirms the presence of compressive residual stress, as well as grain refinement and texturing effects after the peening. Furthermore, the research endeavors to improve their mechanical and electrochemical properties by employing USSP's varied process parameters in a hybrid approach. After undergoing USSP treatment, the average surface roughness was increased by up to 6 µm due to the formation of dimples, while it was 8 µm in the as-cladded and only 1.5 µm after polishing. Furthermore, compared to the as-cladded and polished claddings, the hybrid claddings exhibit a hydrophobic character linked to improved corrosion resistance and better in-depth roughness profiles.

Influence of Cold-Rolling Processes on the Dimensional Accuracy and Roughness of Small-Diameter Thick-Walled Seamless Tubes

Cold pilgering is widely utilized in high-end applications for the precise shaping of seamless tubes due to its capacity for large deformation, which reduces the number of deformation processes and shortens production cycles. However, there is a gap in the research on the cold pilgering of small-diameter, thick-walled seamless tubes, specifically those with an outer diameter–wall thickness ratio of ≤3. In this study, cold pilgering tests were performed on Cr-Mo-V hot-working die steel small-diameter thick-walled tubes. It was discovered that increasing the feed rate results in greater deviations in both inner diameter and wall thickness, although it has little effect on inner wall roughness. In contrast, increasing wall thickness reduction leads to higher wall thickness deviation but reduces inner surface roughness without significantly affecting inner diameter deviation. The study also found that a decrease in the initial inner wall roughness before pilgering results in improved final roughness. Under optimal conditions, the average inner surface roughness Sa can reach 0.177 μm, and small-diameter thick-walled seamless tubes with deviations in the inner diameter and wall thickness of 0.05 mm and 0.03 mm, respectively, are obtained. After tempering at 600 °C, the tensile strength (Rm) and yield strength (Rp0.2) of the cold-pilgered tube reach 1092 MPa and 947 MPa, respectively, and the elongation (δ5%) and impact energy (AkU) increase to 20.4% and 61.5 J, respectively.

The interplay between toothbrush stiffness and charcoal-containing dentifrice on the development of enamel topography changes

BackgroundThis study aimed to investigate the in vitro effect of a charcoal-containing dentifrice with different toothbrush stiffness on enamel.MethodsFour main groups were applied: distilled water, conventional fluoridated toothpaste (Colgate® Total® 12 Clean Mint Toothpaste), charcoal toothpaste (Colgate® Total® Charcoal Toothpaste) and whitening toothpaste (Colgate Total® Advanced Whitening Toothpaste). Three subgroups for each toothpaste were further included according to the toothbrush bristles’ stiffness (soft, medium, and hard). Enamel specimens were subjected to 1,250 and 2,500 cycles of brushing using toothbrushing simulation machine. The average surface roughness change (ΔRa) in nanometer (nm) was measured to estimate the changes following the brushing simulation model. Two-way ANOVA and Tukey tests analyzed the data.ResultsThe type of toothpaste and the bristles’ stiffness were determinant factors in increasing the ΔRa value (P = < 0.05). Generally, charcoal and whitening toothpastes with medium and hard bristles yielded higher ΔRa than fluoridated toothpaste and smooth bristles. Following 1,250 cycles of brushing simulation, charcoal toothpaste did not increase the enamel roughness compared to the controls. However, in prolonged brushing via 2,500 cycles of brushing simulation, using bristles with soft stiffness revealed that charcoal toothpaste was associated with increased surface roughness (55.86 ± 41.18 nm), which was statistically significant (P = 0.024) compared to the negative control. Using bristles with medium stiffness showed that the whitening (68.23 ± 48.58 nm) and charcoal (73.62 ± 34.66 nm) toothpastes significantly (P = < 0.05) increased the enamel roughness compared to the conventional toothpaste (36.53 ± 22.56 nm). There was no significant difference among the groups when brushes with hard bristles were used, as all the groups revealed increased enamel roughness.ConclusionThe use of charcoal and whitening toothpastes increased enamel roughness, particularly with long-term use. The effect of bristle stiffness on enamel roughness was found to vary depending on the type of toothpaste used.

Tensile strain-induced disorder and weak localization in SrRuO3 thin films on (100) KTaO3 substrates

Abstract SrRuO3 (SRO) thin (∼12 nm) films have been grown on KTaO3 (001) substrates by RF magnetron sputtering. The as-prepared films are under enormous in-plane tensile strain, which corresponds to the elastic energy of ∼1.5 MJ. Annealing in oxygen at 900 °C for 6 h relaxes strain, partially lowering the elastic energy. The surface topography shows a transition from granularity as the Ar+O2 pressure increases from 5 mTorr to 200 mTorr, with a simultaneous change in the average surface roughness from 4 nm to 0.8 nm. Annealing transforms the topography to island-type and enhances surface roughness. The films deposited at 5 mTorr are semiconducting, and annealing further enhances the resistivity. The ρ-T of films grown at 200 mTorr shows a metallic behavior with an inflection in the ρ-T at TC ∼ 150 K, FM transition. The low-temperature resistivity upturn shows the disordered nature of these films. The eq. ρ T = 1 σ 0 + a T 1 2 + a 1 T p 2 + b T α (p = 2 &amp; α = 2) describes the transport behavior from 2 K to 300 K of 5 mTorr deposited films. In the 200 mTorr deposited film, the above eq. is valid at T &lt; 95 K with p = 2 and α = 1.5. At TC &lt; T ≤ 300 K, the ρ-T follows eq. ρ T = ρ 0 + ρ 1 T α with α = 1.3 and 1.5 for the as-grown and annealed films. The lower temperature ρ-T upturn appears to have contributions from the disorder-enhanced renormalized e-e interaction (REEI) and weak localization (WL) effects. The magnetoresistance behavior supports a substantial WL effect in the films grown at 200 mTorr. Our results establish a strong correlation between the nature of strain, surface topography, and carrier transport mechanisms.

Nickel-based alloy efficient milling with ceramic tool and experimental verification in closed impeller

Nickel-based alloys are a class of materials that possess exceptional properties, including superior corrosion, oxidation, and fatigue resistance. They are increasingly utilized in high-performance critical components, particularly in the fields of aerospace engines and gas turbines. Nickel-based alloys pose significant challenges during machining due to their high cutting forces and work hardening, leading to low machining efficiency, severe tool wear, and subpar surface quality of the machined parts. To address these challenges, an orthogonal cutting experiment was conducted on GH4061 alloy to evaluate the machining performance by using monolithic ceramic milling tools. The optimal cutting parameters combination for dry cutting of nickel-based alloys was determined. The surface quality was tested and analyzed, including surface micro structure, residual stress, and surface roughness. The machining experiment was conducted on GH4061 closed impeller. The results demonstrated that high-speed cutting was more effective than low-speed cutting in improving the surface quality of the machined part. In the rough processing, monolithic ceramic milling tools was used to quickly remove the excess material. The adhesive and diffusion effects mainly contributing to the wear of the monolithic ceramic tool in GH4061 milling. Average surface roughness 1.41 μm can be obtained through dry milling using a monolithic ceramic tool with cutting speed 602.88 m/min, cutting depth 0.3 mm, cutting width 6 mm and feed per tooth 0.03 mm/z, along with metal removal rate 5184 mm3/min. High cutting speed will resulting in relatively low residual stress in the surface layer as well as a lower thickness of the surface alternation layer. Finally, a physical GH4061 closed impeller was machined to verify the proposed milling method.

Investigation of Electrochemical Discharge Machining for Tungsten Carbide: Effects of Electrolyte Composition on Material Removal Rate and Surface Quality

Abstract Tungsten carbide (WC-Co) with a cobalt binder has been widely used in industrial application. Through their high wear resistance and hardness, which make it a challenge to machine. Electrochemical discharge machining (ECDM) is a newly developed hybrid technique used to machine conductive and nonconductive materials. Tungsten carbide machining is an area that needs more investigation. In this study, different types of electrolytes have been tested in the electrochemical machining of tungsten carbide. It has been concluded that tungsten carbide was successfully machined with electrolytes that were either neutral salts or a combination of neutral salts and hydroxides, the highest material removal rate achieved was (0.09250 g/min), and the average surface roughness achieved in this work was measured at (Ra 0.9275 µm). However, deposition took place on the surface of machined tungsten carbide when the samples were treated with sodium hydroxide and potassium hydroxide. EDX analysis of successfully machined tungsten carbide samples reveal the presence of carbon (C) due to diffusion from the base material and oxygen (O), most likely due to oxidation brought on by the high temperatures utilized. Scanning electron microscopy confirmed that the machined surfaces had craters, pores, restricted microcracks, and re-deposited melt particles, among other things.

Surface Post-Treatments of Different Lattice Structures Manufactured by 3D Printing using Selective Laser Melting

Selective laser melting (SLM) offers great potential for the fabrication of Ti6Al4V lattice structural components, but the resulting surface roughness of the manufactured products severely limits the use of the parts in biomedical applications. To reduce the influence of high surface roughness, the post processing process techniques applicable to all different lattice structures. In this study, two techniques were combined: ultrasonic abrasive flow and electro polishing treatment. To analyze Selective laser melted parts after post processing process, porosity and microstructural analyses were done. Furthermore, checking the influence of Electro polish time on surface of lattice structures. EP treatment conducted, applying a voltage of 20 ,18, and 16(V) And also (8), (6) and (4) minutes sequentially at a temperature of (4-7) C⁰ for HC, FCC, and BCC lattice structure specimens, sequentially. Acid-based electrolyte to perform Electro Polish, its solutions proved to be effective in reducing average surface roughness Ra from 7.325,7.465 and 6.7732.7 μm to 4.661 .3.911 and 4.20 for hexagonal, face center cubic and body center cubic lattice structures. In addition to, Rz from 36.766 ,35.768 and 30.029 to 22.482 ,17.88 and 18.249 μm sequentially. After post processing process, the findings of surface roughness, Young’s modulus, yield strength, and Porosity percentage are compatible with the properties of bone, allowing it to be utilized as a scaffold.

Electrophoretic deposition of polyetheretherketone/polytetrafluoroethylene on 316L SS with improved tribological and corrosion properties for biomedical applications

Introduction316L stainless steel (316L SS) has poor wear and corrosion resistance compared to that of the Cp-Ti and Ti-6Al-4V implants [when studied under a physiological environment using phosphate-buffered saline (PBS)]. However, 316L SS implants are cost-effective. Their wear and corrosion properties can be improved by depositing biocompatible coatings.MethodIn this research work, a polymer coating of polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE) was deposited at optimized parameters (20 V for 3 min) on 316L SS via electrophoretic deposition (EPD). We compared the performance between of the PEEK coating and hybrid PEEK/PTFE coatings for biomedical applications. The PEEK/PTFE coating was sintered at 350°C for 30 min.Results and DiscussionScanning electron microscopy (SEM) analysis revealed that the PEEK/PTFE coating showed a uniform coating with a uniform thickness of ∼80 µm. Fourier transform infrared (FTIR) spectroscopy analysis confirmed the presence of bonds attributed to the PEEK and PTFE coatings. The PEEK/PTFE coating exhibited adequate average surface roughness (Ra) of 2.1 ± 0.2 µm with a high value of contact angle of 132.71 ± 3, indicating the hydrophobic nature of the PEEK/PTFE coating. Scratch tests evaluated that the PEEK/PTFE coating demonstrated a 7 N load, which indicated the good adhesion between the coating and 316L SS. Furthermore, the PEEK/PTFE coating demonstrated good wear resistance, capable of withstanding a 7 N load under dry conditions, and showed a specific wear rate of ∼0.0114 mm3/Nm. Electrochemical analysis conducted using the phosphate-buffered saline (PBS) solution demonstrated that the corrosion rate of 316L SS was reduced from 0.9431 mpy to 0.0147 mpy by depositing the PEEK/PTFE coating. Thus, the developed coatings present suitable wear and corrosion resistance and are thus considered for potential orthopedic applications.

Performance analysis of uncoated and coated (TiN-, TiAlN-) carbide drills in drilling graphene-reinforced GF/epoxy nanocomposites: Analytical and experimental study

The present study aims to investigate the performance of conventional uncoated and coated (TiN, TiAlN) solid carbide drill tools in drilling bi-directional graphene-reinforced (2 wt.%) glass fiber (GF)/epoxy polymer nanocomposite laminate with two distinct lamination schemes ([0/90]12S and [0/90/±45]6S). Performance measures included thrust force, torque, tool flank wear, peak acoustic emission, root mean square (RMS) of acoustic energy, and average surface roughness. Moreover, the delamination that occurs beyond the critical value of thrust force (computed analytically) has also been addressed. Optimized drilling parameters were used for experimentation to minimize thrust force and torque simultaneously. Both TiN and TiAlN-coated carbide drills outperformed uncoated carbide drills for fewer holes (around 25 for TiN and about 40 for TiAlN), but their performance deteriorated with more holes due to coating chipping or peeling from the original tool material. The (0/90 ± 45)6S graphene-reinforced layup showed less tool wear, deterioration, and acoustic emission energy compared to the (0/90)12S neat layup. TiAlN-coated drills exhibited the smallest wear on the flank face followed by TiN-coated and uncoated carbide drills. Moreover, the smoothest cut surface throughout the 300 holes drilled, averaging 1.5 µm to 1.8 µm in surface roughness, was observed with the TiAlN-coated drill. Therefore, the TiAlN-coated drill is recommended for drilling a larger number of holes due to its reduced tool wear, smoother cut surfaces, and better form accuracy with minimal delamination.